Cardiac Catheterization

This test is performed in the cardiac catheterization laboratory ("cath lab") by a Reference cardiologist Opens New Window. See a picture of a Reference cardiac catheterization lab Opens New Window Reference Opens New Window.

You will be asked to lie on a flat table under a large X-ray machine. Several small metal leads (electrodes) will be attached to your legs and arms with a special paste or gel. These leads are connected to an Reference electrocardiogram (EKG, ECG) Opens New Window machine that continuously records the electrical activity of your heart during the test.

A device called a Reference pulse oximeter Opens New Window that measures oxygen levels in your blood and monitors your pulse may be clipped to your finger.

An intravenous (Reference IV Opens New Window) needle will be inserted into a vein in one of your arms to give you fluids or medicine during the procedure. You will receive a medicine to help you relax (Reference sedative Opens New Window) through the IV line. You may be awake during the procedure. But even if you are awake, the sedative may make you so sleepy that you may not remember much about the procedure.

The thin flexible tube (cardiac catheter) is usually inserted in your groin (femoral artery). Other sites that may be used are the crease of your elbow (brachial artery), your wrist (radial artery), or your neck. The catheter insertion area will be shaved and cleansed with an antiseptic solution before the test. Sterile towels will be draped over you, except for the area over the catheter insertion site.

A Reference local anesthetic Opens New Window will be injected into the skin at the insertion site. A blood vessel is punctured by a special needle or exposed by making a small cut in the skin so that the catheter can be passed into the blood vessel. The catheter is slowly advanced through the blood vessel into your body. The catheter tip is moved into various positions in the heart's vessels and chambers while the doctor watches its progress on the imaging screen. Pressures within the heart chambers can be measured. Blood and heart tissue samples may also be removed through the catheter, if necessary.

See a picture of the Reference placement of a cardiac catheter Opens New Window Reference Opens New Window.

You may be asked to hold your breath or move your head slightly to provide clear views of the heart and its blood vessels.

A small amount of dye (contrast material) will be injected through the catheter into your heart chamber or one of your coronary arteries. Pictures show the arteries as the dye moves through them. You may be asked to cough to help clear the contrast material out of your heart or breathe deeply and hold your breath.

It is important to lie as still as possible, since motion can make the images blurry or hard to interpret. A health professional will help you stay comfortable and will help you resist the urge to move around. Be careful not to touch the sheets or reach for your groin area because you may contaminate the sterile areas and increase the risk of infection.

Your doctor may allow you to watch the video monitor so you can see the images of your heart and coronary arteries.

You may be given nitroglycerin to help open up your coronary arteries. Or you may be given an injection of a medicine that causes the coronary arteries to narrow. You may be asked to breathe into a special mouthpiece to help measure the flow of oxygen in your circulating blood.

After the test

The catheter will be removed from the insertion site. To prevent bleeding, the site may need to be closed using pressure, stitches, or a special seal. For example, if the catheter was inserted in your wrist or groin, firm pressure will be applied to the area for about 10 minutes to stop the bleeding. Then a pressure dressing will be placed over the area. If the catheter was inserted in your elbow, a few stitches will be used to close the wound.

The test takes about 30 minutes. But you need time to get ready for it and time to recover. It can take up to 6 hours total. The length of the test is not an indication of the seriousness of your condition. After the test, you will be taken to an observation room and a health professional will periodically monitor your heart rate, blood pressure, and temperature and check for signs of bleeding at the insertion site. The pulse, color, and temperature of the arm or leg in which the catheter was inserted will also be checked periodically.

If the catheter was inserted in your leg, you may have to lie in bed with your leg extended for several hours (such as 4 to 12 hours), depending on the exact procedure used and your medical condition. After that, you can move about freely, but you should avoid strenuous activity for at least 1 to 2 days. A child who has had cardiac catheterization may need to be held by a parent for several hours after the test to prevent the child from moving his or her leg.

You should drink plenty of liquids for several hours after the test. This will prevent Reference dehydration Opens New Window and help flush the contrast material out of your body.

Depending on the results of the test, you may be sent home either after a short observation period (such as 6 hours) or on the next day. If any stitches were placed in your arm, they may be removed in 5 to 7 days.

If you are breast-feeding, use formula for 1 to 2 days after the test.

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